MCU hangs after connecting disconnecting and again connecting

[Rajbir Singh]

Hi, there

I am using nrf52832 chip on a custom hardware and also using softdevice 132 to send data to an app.

I need to send data from app to MCU and vice-versa and it is working fine but the problem is that after disconnecting if I again try to connect to the app the MCU hangs.

This is my main function below

int main(void)
{
  uint8_t cntr = 0, kk;

  peripheral_init();
    Time_Read();
    UID_read();
    ble_init();
    advertising_start();
    Clear_Screen(0);

    while (1)
    {
      if (!ble_con_sta)
      {        
        home_scrn();
        cntr++;

        if ((cntr % 10) == 0)
        {
          Time_Read();
          if (scan_fingerprint())
          {
            advertising_start();
            match_fingerprint();
            while (scan_fingerprint());
            Clear_Screen(0);
          }
        }

        if (cntr > 200)
        {
          idle_state_handle();
          cntr = 0;
        }
        nrf_delay_ms(1);
      }
      else
      {
        display_app_acess();
      }
    }
  
  //for (;;)
  //{
  //  idle_state_handle();
  //}
}

As you can see I called the advertising_start() function before while loop once and after I have used finger print sensor as button to match fingerprint and also to start advertising again.

In my application  I have to send/receive data from app 3 or 4 times a day,but while testing I am connecting and disconnecting from app frequently to test but MCU hangs after multiple connecting and disconnecting.

I am facing two issues

1. Multiple connecting and disconnecting hangs MCU

2. After APP_ADV_DURATION completed and I try to call advertising_start function MCU hangs

3. I have to call match fingerprint function multiple time if my fingerprint doesn't match and that will call the advertising_start function again

Please suggest something to solve this problem

[Einar Thorsrud]

Hi,

There is normally no problem disconnecting and reconnecting an arbitrary number of times, nor should restarting to advertise be a problem. I think the next step should be to debug and see which state the application is in when you write it "hangs". Is an APP_ERROR_CHECK hit, for instance (see An introduction to error handling in nRF5 projects)? What else do you find by debugging?

[Rajbir Singh]

Yes,it hangs during advertising start function

[Einar Thorsrud]

I see. There is nothing here that indicates why, though. Please elaborate and show what you have found during debugging. The CPU never just "hangs", so there must be something going on. Is an error check hit, like I asked for before? Or is there a busy wait somewhere? Or something else? Only debugging will point in the direction you must look next.